警惕 (jǐng tì) is a verb meaning 'to be vigilant' or 'to stay on guard.' It combines two characters: 警 (jǐng), meaning 'to warn' or 'alert,' and 惕 (tì), meaning 'to be cautious' or 'wary.' Together, they emphasize an active, conscious state of watchfulness—often in response to potential danger, deception, or harm. Unlike simple caution, 警惕 implies sustained attention and mental readiness, especially when risks are subtle or hidden.

This word appears frequently in health, safety, and public awareness contexts—for example, warning people about scams, disease prevention, or environmental hazards. It’s commonly used in formal notices, news reports, and official guidance. While it can describe personal vigilance, it’s rarely used for momentary reactions; instead, it conveys a deliberate, ongoing attitude. The structure often follows subject + 警惕 + (against/for something), and it frequently pairs with verbs like 提高 (to raise), 保持 (to maintain), or 加强 (to strengthen).